As is well known in the electric utilities industry, defects in high voltage lines or cables or transformers which may result in localized power outages are relatively common occurrences. When such a defect manifests itself, monitoring equipment at the local electric utility company is usually operable to provide the general location of the defect. However, it then typically becomes necessary for electric company personnel to pinpoint the precise location of the defect. Even in those instances where the defect does not manifest itself as a power outage, there is still a resultant degradation in the transmission efficiency of the cable, or efficiency of the high voltage equipment. Indeed, it is known in the electric utilities industry for high voltage equipment and transmission lines to be routinely inspected for defects by electric utility company personnel.
A common trait of defective high voltage cables, transformers or equipment is that they give off an arc or corona discharge. Though this corona discharge generates ultraviolet radiation in a prescribed spectral region, the same is typically not visually observable, thus necessitating that other measures be employed to pinpoint the precise location of the defect within the high voltage cable, transformer or equipment. The present invention provides a corona discharge detection device which is operable to sense or detect a corona discharge at substantial distances, and is further specifically configured to ignore the effects of background optical radiation, and thus not generate false alarms as a result thereof. More particularly, though being operable to detect the corona discharge or arc of a defective high voltage cable, transformer or equipment at distances of up to about 300 feet, the present detection device is not triggered as a result of sunlight, objects heated to high temperatures from sunlight, heated car engines, building heaters, or incandescent or fluorescent lamps. The present detection device may also be configured to determine with accuracy the point of origin of the corona discharge, thus allowing for the expedited repair of the high voltage cable, transformer or equipment. These, and other advantages associated with the present detection device, will be discussed in more detail below.